NONGROWTH ASSOCIATED PRODUCTION OF ENZYMES IN SOLID-STATE FERMENTATION SYSTEM - ITS MATHEMATICAL-DESCRIPTION FOR 2 ENZYMES PRODUCED BY BACILLUS-LICHENIFORMIS M27

Logistic model, based on more general and realistic assumptions, has b een derived to express the production of two non-growth associated enz ymes by Bacillus licheniformis M27 in a solid state fermentation syste m. The model explained the production of alpha-amylase and neutral pro tease with correlation coefficients ranging between 0.974 and 0.985 in basal and standardized wheat bran media. It is apparent from the valu es of parameters in the model that the rate constant in standardized m edium was lower (0.15 l/h(-1)) than in the basal medium (0.32 l/h(-1)) , though higher maximum enzyme titres (1.7 times) were observed in the former medium. The data thus indicate dependence of enzyme titres on the maximum biomass formed. The model represents a significant advance in model formulation as it recognizes and takes care of all other pro ducts (enzymes etc) formed during fermentation. The model may prove us eful in optimizing product synthesis, design of bioreactor and determi nation of harvest time, especially due to its adequacy and efficiency. Models for predicting product formation in solid state fermentation s ystem are scarce and confined to fungal fermentations. No such model f or bacterial solid state fermentation system was available earlier.